ann11077 — Announcement

Café & Kosmos 8 November 2011

Mysterious supernovae — secrets of the most powerful cosmic explosions

7 November 2011

Colliding and exploding stars, which we witness as supernovae and gamma-ray bursts, generate the most powerful and brightest surges of energy in the Universe. During the very short time needed for these explosions to produce a neutron star or a black hole, they release more energy than the Sun during its whole life. Their observations, billions of light-years away, give us direct insights on the accelerated expansion of the cosmos.

As destructive as these explosions are, they nevertheless play an important role in the evolution of their host galaxy. Without them, there would be no planets, no plants, no animals. The explosions drive the cycle of matter in the galaxy: the chemical elements heavier than hydrogen and helium, produced by previous generations of stars and supernovae, are dispersed into space by these stellar explosions, so they can be incorporated into new stars and condense into planetary systems.

The astrophysicist Hans-Thomas Janka has explored the complex physical processes taking place in supernova explosions for many years using computer models. He will tell the next Café & Kosmos audience of this fascination for these events, and explain some of the challenges he faces when modelling them in three dimensions. He will also discuss the hopes (and fears) caused by an upcoming explosion in our Milky Way.